<template>
  <div id="app">
    <div id="nav">
    </div>
    <router-view/>
  </div>
</template>

<script>
    export default {
        created() {
            //在页面加载时读取sessionStorage里的状态信息
            if (sessionStorage.getItem("username")) {
                this.$store.replaceState(
                    Object.assign(
                        {},
                        this.$store.state,
                        JSON.parse(sessionStorage.getItem("username"))
                    )
                );
            }

            //在页面刷新时将vuex里的信息保存到sessionStorage里
            window.addEventListener("beforeunload", () => {
                sessionStorage.setItem("username", JSON.stringify(this.$store.state));
            });
        },
    }
</script>

<style lang="scss">
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
}

#nav {
  padding: 30px;

  a {
    font-weight: bold;
    color: #2c3e50;

    &.router-link-exact-active {
      color: #42b983;
    }
  }
}
</style>
